Wide variation in asymptomatic PSA testing between GP practices

Researchers have uncovered wide variation between GP practices in use of PSA testing in men who are asymptomatic for prostate cancer.

A study designed to look at how many men without symptoms were diagnosed with prostate cancer after having a test found a 13-fold variation between practices in how frequently testing was done.

The analysis from researchers around the UK also found that one in five patients with prostate cancer were diagnosed after an asymptomatic PSA test – fewer than had previously been thought.

All 9,837 men with a diagnosis of prostate cancer in the 2018 English National Cancer Diagnosis Audit were included in the study.

Of those 19.2% had been diagnosed following PSA testing but with no recorded symptoms in their patient records, the study found.

Half of those were aged 50 to 69 years, the team reported in the British Journal of General Practice.

Younger age, non-white ethnicity, lower deprivation, and lower comorbidity count were associated with an increased likelihood of diagnosis following asymptomatic PSA testing, the analysis showed.

But the researchers could not find a clear explanation for the large variation in PSA testing rates seen between practices.

The findings highlight ‘the ongoing lack of clarity’ around prostate cancer screening practice in the UK, they concluded.

Yet at a patient level, the findings support other work that had consistently shown that men from more deprived areas are less likely to undergo PSA testing, they added.

‘Patient factors were found to have a profound impact on PSA testing and are, therefore,
likely to play a role in driving prostate cancer inequalities.

‘A more consistent approach to asymptomatic PSA testing with initiatives to raise awareness about prostate cancer, communicating the pros and cons of undergoing PSA testing among men, and addressing barriers to accessing primary care may help to reduce such inequalities,’ they said.

The UK National Screening Committee does not currently recommend screening for prostate cancer.

Instead, the Prostate Cancer Risk Management Programme (PCRMP) provides guidance for GPs on how to counsel asymptomatic men on the potential benefits and harms of PSA testing so they can make an informed choice.

The committee has commissioned a modelling study after receiving applications to review various strategies to offer prostate cancer screening. 

A range of options is under consideration, including a targeted service for men at higher risk due to factors such as ethnicity and family history.   

The committee is also reviewing research suggesting MRI scans may be a way to more accurately detect prostate cancer.

Study leader Professor Gary Abel, professor of medical statistics at the University of Exeter, said: ‘We were surprised by the extent of the variation we saw between practices, which speaks to the ongoing lack of clarity around prostate cancer screening in the UK.

‘We know that men from deprived areas are at highest risk of developing late-stage prostate cancer and were less likely to be investigated.

‘It is hard to know what to do when the evidence isn’t clear but a more consistent approach to testing people without symptoms is needed to help redress this imbalance.’

Co-author Dr Sam Merriel, an NIHR academic clinical lecturer at the University of Manchester and a practicing GP, said: ‘Inconsistencies in local, regional, and national guidance mean it is really down to individual GPs to make decisions on which patients to test, how often to test, and what PSA thresholds warrant urgent referral for suspected cancer. 

‘These inconsistencies may be contributing to the variation in whether GPs are detecting prostate cancer in patients who do not have symptoms.’

Naser Turabi, director of evidence and implementation at Cancer Research UK, said: ‘This study highlights variation in the detection of prostate cancer through PSA testing in men with no symptoms.

It was understandable why some men asked for a test but research was needed to find better ways to detect and treat prostate cancer, he added.

‘The evidence shows that it can cause more harm than good for men who have no prostate cancer symptoms. The UK National Screening Committee is constantly reviewing the best evidence and doesn’t currently recommend screening for prostate cancer.’